Merge remote-tracking branch 'origin/master' into codex/trim-ai-prose

# Conflicts:
#	docs/AGENTS.md
#	docs/config-catalog.md
#	packages/bash/bash-sandbox/src/index.ts
#	packages/bash/bash/src/session-mode.ts
#	packages/bash/tool-bash/README.md
#	packages/code-runtime/code-runtime-worker/README.md
#	packages/compact/compact/src/index.ts
#	packages/core/agent-core/README.md
#	packages/hooks/hooks-claude/src/config.ts
#	packages/hooks/hooks-claude/src/index.ts
#	packages/hooks/hooks-codex/src/config.ts
#	packages/hooks/hooks-codex/src/index.ts
#	packages/llm/llm/README.md
#	packages/session-persistence/session-persistence-jsonl/README.md
#	packages/session-persistence/session-persistence/README.md
#	packages/skill/skill-local/README.md
#	packages/support/acp-snapshot/README.md
#	packages/support/invariants/src/index.ts
#	packages/ui/acp/README.md
#	packages/ui/jsonrpc-agent/README.md
#	packages/ui/jsonrpc/README.md
#	packages/ui/permission/README.md
#	packages/ui/user-approval/README.md
#	packages/ui/user-interaction/README.md
#	packages/web/web-search-deepseek/README.md

packages/ui/acp-agent/README.md

@@ -15,6 +15,7 @@ stdout is the ACP JSON-RPC channel, so the cluster is defined as much by what it
 | `@deepseek-ai/dsh-session-persistence-jsonl` | durable JSONL session log (the bridge advertises `loadSession`) |
 | `@deepseek-ai/dsh-acp` | the bridge that owns stdout for JSON-RPC and provides ACP-backed user answers when a leaf explicitly exposes a user-question tool |
 | ~~`@deepseek-ai/dsh-tool-ask-user`~~ | **omitted by default** — ACP elicitation support is still client-dependent, so leaves must opt in deliberately |
+| ~~`@deepseek-ai/dsh-user-approval`~~ | **omitted by default** — permission policy is deployment-specific; sandbox/approval leaves opt in and the ACP bridge then supplies the answerer |
 | ~~console logger~~ | **omitted** — it writes to stdout and would corrupt the protocol frames ([the stdout-purity footgun](../acp/README.md)) |
 | ~~`hmr`~~ | **omitted** — the editor owns the subprocess |
 
@@ -27,6 +28,8 @@ Because the package wires no logger entry, an ACP leaf has **nothing to get wron
 | `model` | (required) | the per-session agent template the bridge creates agents from |
 | `persona` | — | the deployment persona template (may reference `{{model}}`/`{{cwd}}`), routed to `dsh-system-prompt` |
 | `toolOrder` | — | explicit model-facing tool order (a name list with one `'<unlisted-tools>'` rest entry; absent — lexicographic; an unregistered name fails each turn at prompt assembly), routed to `dsh-system-prompt` |
+| `tools` | `{ mode: 'native' }` | tool-registry presentation config (`native` / `code` / `both`), routed through `dsh-agent-core` |
+| `skills` | owner defaults | registry-cache, local-provider, and model-facing skill-tool config, routed through `dsh-agent-core` |
 | `persistenceRoot` | `./.sessions` | the JSONL backend's root directory |
 
 The leaf supplies the swappable backends: an LLM adapter (`llm-deepseek` for the real model, `llm-replay` for keyless snapshot replay) and a bash executor.
@@ -42,3 +45,13 @@ The leaf supplies the swappable backends: an LLM adapter (`llm-deepseek` for the
 Run it under `node --expose-internals`: the cordis Loader resolves the config's bare plugin specifiers through its internal module loader, active only under that flag. (`demo:acp` runs under tsx, whose tsconfig `paths` map resolves them instead.)
 
 All diagnostics go to **stderr** — stdout is the protocol.
+
+## Model Experience
+
+Indirectly, through `dsh-agent-core` and `dsh-acp`, which compose each ACP agent's prompt, tools, and message history; this app bundle adds no model-bound content itself.
+
+## Known Limitations and Deferred Work
+
+- **JSONL persistence is baked in** — config chooses its root but cannot select a different backend; that requires a sibling entry or differently composed app package.
+- **User-question and approval mechanisms are omitted by default** — the bridge can answer both when their services/tools are composed, but this front door does not enable those deployment policies itself.
+- **A leaf can still corrupt stdout** — the app mounts no console logger, but it cannot prevent a sibling leaf entry from writing non-protocol bytes to the ACP channel.

packages/ui/acp/README.md

@@ -46,7 +46,7 @@ Background bash tasks use the session id as an opaque owner token, so one sessio
 
 ## Per-session cwd
 
-`session/new` records the request's absolute cwd in the session header. `session/load` requires an absolute request cwd matching persisted metadata and rejects missing or mismatched metadata before constructing an agent. Bash defaults to that workspace; an explicit relative workdir resolves against it. `additionalDirectories` remains unsupported.
+`session/new` records the request's absolute cwd in the session header. Before constructing an agent, `session/load` uses persisted metadata to require an absolute request cwd that matches the stored one. Bash defaults to that workspace; an explicit relative workdir resolves against it, and multiple sessions may use different workspaces. `additionalDirectories` remains unsupported.
 
 ## Tool-call presentation
 
@@ -54,7 +54,7 @@ Tools return provider-neutral `generic`, `terminal`, or `diff` render intents fr
 
 ## Terminal card (capability-gated)
 
-When the client advertises `_meta.terminal_output`, terminal intents map to Zed's terminal info, output, and exit metadata; result text is omitted because ACP updates replace call content. Other clients receive a generic card and fenced console fallback. Session creation snapshots the capability so call and result agree. The command still executes through the harness, not ACP terminal creation. See the [terminal-rendering RFC](../../../docs/rfc/implemented/feature/2026-06-18-acp-terminal-and-tool-rendering.md).
+When the client advertises `_meta.terminal_output`, terminal intents map to Zed's terminal info, output, and exit metadata. The bridge resolves relative cwd against the session, places the description before the terminal block, and omits result content because ACP updates replace call content. Other clients receive a generic card and bridge-derived fenced console fallback. Session creation snapshots the capability so call and result agree. The command still executes through the harness, not ACP terminal creation. See the [terminal-rendering RFC](../../../docs/rfc/implemented/feature/2026-06-18-acp-terminal-and-tool-rendering.md) and [render-intent RFC](../../../docs/rfc/implemented/architecture/2026-07-02-tool-render-intent-union.md).
 
 ## Settle-exactly-once
 
@@ -68,10 +68,6 @@ For a bridge-owned call, the [approval seam](../user-approval/README.md) maps `a
 
 Disposal and client disconnect share one memoized teardown. It cancels pending prompts and disposes all owned agent handles in parallel, waiting for loop exit and final flush before registry removal. Mid-turn teardown records `disposed`; `session/cancel` records `aborted`.
 
-## Known limitations (tracked TODOs)
-
-- **`additionalDirectories`** — rejected. A session operates in its single `cwd` (see Per-session cwd); widening the tool/filesystem scope to extra roots is a separate sandbox concern, not yet implemented.
-
 ## stdout is the protocol
 
 The JSON-RPC frames go on stdout, so this plugin MUST run in an example that loads **no stdout logger** (the console logger writes to stdout and would corrupt the frames). The guarantee is config-only — see `examples/acp-agent` (no console logger) and [ACP support risks](../../../docs/rfc/implemented/feature/2026-06-14-acp-agent-client-protocol.md#risks). A stderr exporter is fine for logging.
@@ -90,3 +86,37 @@ The JSON-RPC frames go on stdout, so this plugin MUST run in an example that loa
   }
 }
 ```
+
+## Model Experience
+
+### User messages
+
+**What the model sees**: Each ACP `session/prompt` becomes an agent user message: text passes through verbatim and each `resource_link` becomes exactly a leading newline, `[resource_link name=<JSON-string> uri=<JSON-string>]`, and a trailing newline. Unsupported image, audio, and embedded-resource blocks are rejected rather than silently omitted.
+
+**Token effect**: Prompt tokens are data-dependent and remain in that session's history until compaction. Concurrent ACP sessions keep separate contexts.
+
+### Human answers and permission decisions
+
+**What the model sees**: When optional consumers are loaded, ACP form answers become the exact JSON shape documented by `dsh-tool-ask-user`. Failures become `Error: ACP user questions must come from an agent-owned request`, `Error: ACP user question has no matching session`, `Error: ACP elicitation request failed`, `Error: ask_user_question was cancelled by the user`, `Error: ask_user_question returned no answer`, or `Error: ask_user_question was aborted before the user answered`. Permission decisions control whether another tool yields success or denial. ACP tool cards, terminal output, diffs, and streamed session updates are UI-only.
+
+**Token effect**: Answer, error, and denial text enters context only through the owning tool result; presentation metadata adds zero model tokens.
+
+### Permission preset switches
+
+**What the model sees**: `session/set_config_option` emits no model message itself. When `dsh-permission` is composed, the bridge writes the selected preset through that service; the resulting model-visible policy prompt and change notice belong to [`dsh-user-approval`](../user-approval/README.md), while sandbox-mode effects belong to [`dsh-tool-bash`](../../bash/tool-bash/README.md). The ACP `Permissions` select, its option descriptions, pending idle value, and refreshed config response remain client-only.
+
+**Token effect**: Zero direct tokens from the ACP option or the log-only `permission/preset` event. Downstream cost is limited to the owning plugins' policy prompt, conditional retained change notice, and any changed tool outcome.
+
+### Loaded sessions
+
+**What the model sees**: `session/load` resumes the persisted log, after which the loop sends its reconstructed history and request header. Replaying that log to the editor is not an extra model message.
+
+**Token effect**: Restored context has the persistence and session packages' normal retained cost; ACP replay to the client adds none.
+
+## Known Limitations and Deferred Work
+
+- **`additionalDirectories`** — rejected. A session operates in its single `cwd` (see Per-session cwd); widening the tool/filesystem scope to extra roots is a separate sandbox concern, not yet implemented.
+- **Prompt content is `text` + `resource_link` only** — image, audio, and embedded-resource blocks are rejected, as is a non-empty `mcpServers` list at `session/new`.
+- **One configured `model` for every created session** — per-session model selection has no config or protocol surface here yet.
+- **Terminal cards render completed output** — live incremental streaming and command classification are named follow-ups of [the terminal-rendering RFC](../../../docs/rfc/implemented/feature/2026-06-18-acp-terminal-and-tool-rendering.md).
+- **Permission answers are one-shot only** — the bridge offers `allow_once` / `reject_once`; durable `allow_always` grants and their storage/revocation policy remain deferred to the approval seam.

packages/ui/app-boot/README.md

@@ -13,3 +13,13 @@ Shared boot glue for the app bins ([`dsh-stdio-agent`](../stdio-agent/README.md)
 Two failure classes the guards handle: `loader.await()` swallows init rejections (`Promise.allSettled`) — Node still exits non-zero on the resulting unhandled rejection, and `installFailLoud` replaces the noisy dump with one labelled line and a guaranteed `exit(1)`; a failed plugin IMPORT is only logged by the Loader (the process would otherwise exit 0 on a usable config typo), leaving a fiber-less entry that `assertEntriesLoaded` turns into a `boot()` rejection.
 
 Bare plugin specifiers in a config (`@deepseek-ai/dsh-*`) resolve through the cordis Loader's internal module loader, active only under `node --expose-internals`; the bins' subprocess smokes exercise that path, while this package's unit suite drives `boot()` in-process against configs with relative specifiers.
+
+## Model Experience
+
+Indirectly, through the plugin tree it loads, which determines the prompts, schemas, messages, and model adapter in the resulting application.
+
+## Known Limitations and Deferred Work
+
+- **Bare package specifiers depend on Loader internals** — production bins need `node --expose-internals`; an in-process caller without it must use resolvable relative/file specifiers or tsx path mapping.
+- **Snapshot replay swapping is basename-specific** — only a config ending in `cordis.yml` or `cordis.yaml` maps to the sibling `cordis.snapshot.yml`; custom config names require caller-managed selection.
+- **Environment loading is cwd-scoped and optional** — the helper loads one `.env` file and warns on failure; it does not search parents, merge profiles, or validate required variables.

packages/ui/jsonrpc-agent/README.md

@@ -15,3 +15,13 @@ stdin EOF and `SIGTERM` dispose the root to quiescence and exit 0; `SIGINT` exit
 ## stdout is the protocol
 
 stdout carries only JSON-RPC frames. The bin and boot guards diagnose on stderr, and the config must omit stdout loggers.
+
+## Model Experience
+
+Indirectly, through the plugins loaded from the external `cordis.yml`, which own every model-bound prompt, schema, message, and result; this bin adds none of its own.
+
+## Known Limitations and Deferred Work
+
+- **The bin cannot prove that the config serves JSON-RPC** — a valid config with no `dsh-jsonrpc` entry boots successfully and serves nothing.
+- **No built-in or default config exists** — every launch must provide `DSH_CORDIS_CONFIG` or a positional path, and deployment owns the complete plugin tree and stdout discipline.
+- **stdin EOF cuts off in-flight work** — client disappearance disposes the root immediately; callers that need orderly completion use the protocol-level `shutdown` request.

packages/ui/jsonrpc/README.md

@@ -21,3 +21,17 @@ A `shutdown` request flushes its response, disposes the plugin fiber, then exits
 ## Wire notes
 
 `initialize.serverInfo.name` is the wire-stable `deepseek-harness-sdk-runtime`. Each session permits one in-flight prompt; overlap fails immediately, other sessions remain independent, and the session is reusable after settlement. Persistence roots and deployment persona remain in `cordis.yml`.
+
+## Model Experience
+
+### SDK user message
+
+**What the model sees**: For each accepted `session/prompt`, the conversation model receives the caller-supplied `contentBlocks` verbatim as one user message in that SDK session. This package adds no system-prompt prose or tool schema; those come from the plugins in the surrounding `cordis.yml`.
+
+**Token effect**: Data-dependent user-message tokens enter retained session history and are resent on later turns until another package compacts them. The JSON-RPC frames, session notifications, and server bookkeeping add zero model-context tokens.
+
+## Known Limitations and Deferred Work
+
+- **The wire has no per-session close or prompt-cancel method** — SDK-created agents remain live until process shutdown, and one accepted prompt runs to agent idle before that session accepts another.
+- **stdout purity is deployment-enforced** — a surrounding config can still load a stdout logger and corrupt the JSON-RPC channel; this plugin does not inspect or veto sibling loggers.
+- **Automatic adapter mounting is DeepSeek-specific** — `initialize` can reuse any pre-registered model adapter, but its only fallback mounts `dsh-llm-deepseek`.

packages/ui/permission/README.md

@@ -4,4 +4,14 @@ User-facing permission presets through `ctx.permission` ([`PermissionService`](s
 
 `set(session, name)` records a changed selection in a log-only `permission/preset` event, then calls each knob's setter only when its effective value changes. The selection event precedes the knob events and preserves user intent when presets share a bundle; a net-zero selection appends nothing. `current(events)` prefers a still-matching recorded selection, then the first matching table entry, and otherwise returns `custom`. Clients may display `custom` as the current value, but cannot select it.
 
-The service requires a confining `ctx.bash` executor and `ctx.approval`. A table entry named `custom` throws at load; composition defaults outside the table instead make a zero-event session derive `custom`. See [the acp-agent example](../../../examples/acp-agent/) for the composition and [the sandbox RFC](../../../docs/rfc/implemented/feature/2026-07-06-sandbox.md) for the switching design.
+The service requires a confining `ctx.bash` executor and `ctx.approval`. A table entry named `custom` throws at load; composition defaults outside the table instead make a zero-event session derive `custom`. See the [acp-agent composition](../../../examples/acp-agent/) and [sandbox switching design](../../../docs/rfc/implemented/feature/2026-07-06-sandbox.md).
+
+## Model Experience
+
+Indirectly, through `dsh-user-approval` and `dsh-tool-bash`, which render the approval-policy prompt, switch notice, and sandboxed tool outcomes selected by this service's knob events; `permission/preset` itself is log-only.
+
+## Known Limitations and Deferred Work
+
+- **Only two mechanism knobs are bundled** — presets select sandbox mode and approval policy; an agent/profile choice is not part of `PresetSpec` yet.
+- **`custom` is derived-only** — callers can switch away from an unmatched knob combination but cannot target or persist a named custom preset through this service.
+- **The preset table is process-level** — configuration is fixed for the plugin lifetime; changing available presets requires reloading the plugin.

packages/ui/stdio-agent/README.md

@@ -26,8 +26,10 @@ The leaf `cordis.yml` supplies only the **swappable backends** — an LLM adapte
 | Key | Default | Routed to |
 |---|---|---|
 | `model` | (required) | the pre-created `main` agent's model |
-| `persona` | — | the deployment persona template (may reference `{{model}}`), routed to `dsh-system-prompt` |
+| `persona` | — | the deployment persona template (may reference `{{model}}`/`{{cwd}}`), routed to `dsh-system-prompt` |
 | `toolOrder` | — | explicit model-facing tool order (a name list with one `'<unlisted-tools>'` rest entry; absent — lexicographic; an unregistered name fails each turn at prompt assembly), routed to `dsh-system-prompt` |
+| `tools` | `{ mode: 'native' }` | tool-registry presentation config (`native` / `code` / `both`), routed through `dsh-agent-core` |
+| `skills` | owner defaults | registry-cache, local-provider, and model-facing skill-tool config, routed through `dsh-agent-core` |
 | `persistenceRoot` | `./.sessions` | the JSONL backend's root directory |
 | `welcome` | `ready.` | the stdin-chat banner |
 | `resumeSessionId` | — | resume a persisted session id instead of starting fresh (sourced from an env var in the leaf) |
@@ -63,3 +65,23 @@ Fresh stdio sessions use the process launch directory as `session.header.cwd`, s
 ```
 
 Swap `llm-deepseek` for a `mock-llm` leaf plugin and you have the echo demo — "swap the backend, keep the app".
+
+## Model Experience
+
+### Composed terminal agent request
+
+**What the model sees**: Through `dsh-agent-core`, the `main` agent receives the harness identity, configured persona, skill catalog, and visible tools; this app also composes the generated [`ask_user_question` schema](../../../docs/tool-catalog.md#deepseek-aidsh-tool-ask-user). Each readline submission becomes a user message.
+
+**Token effect**: Child prompt and schema costs repeat per request; user input and tool history grow until compaction. The welcome banner, logger output, and rendered transcript are terminal-only and add zero model tokens.
+
+### Human-answer result
+
+**What the model sees**: Through `dsh-tool-ask-user`, successful terminal answers use that package's exact compact JSON shape. Interruption becomes exactly `Error: ask_user_question was interrupted before the user answered`; a closed stdin becomes `Error: ask_user_question cannot be answered because stdin is closed`.
+
+**Token effect**: Only a completed or failed tool call adds retained result tokens; prompts printed while waiting are terminal-only.
+
+## Known Limitations and Deferred Work
+
+- **One pre-created `main` agent drives the readline UI** — there is no multi-session or concurrent-agent surface in this app; a run is one conversation.
+- **The front-door cluster is fixed in code** — the JSONL persistence backend and the ask-user tooling are baked; a different composition is a leaf-level sibling entry or another app package.
+- **The question tool is not an approval answerer** — this app mounts `user-interaction` and `ask_user_question`, but not `ctx.approval`; a `tools/pre-execute` `ask` therefore fails closed unless the leaf composes an approval service and terminal answerer.

packages/ui/tool-ask-user/README.md

@@ -18,3 +18,22 @@ The tool calls `ctx.userInteraction.ask()` and returns JSON text shaped as `{ "a
 ## Role
 
 This is the consumer package for the user-interaction seam. It does not render UI and does not know how input is collected; it only translates model arguments into `AskUserQuestionRequest` and returns the human answer to the agent loop.
+
+## Model Experience
+
+### Tool schema
+
+**What the model sees**: The model sees the generated [`ask_user_question` schema](../../../docs/tool-catalog.md#deepseek-aidsh-tool-ask-user), including question ids, prompts, headings, options, and multi-select flags.
+
+**Token effect**: Fixed schema cost on every request where the tool is visible.
+
+### Tool-call history and result
+
+**What the model sees**: The model's full questions remain in the assistant tool-call arguments. After the human answers, the next step sees compact JSON in the exact shape `{"answers":[{"id":"<id>","selected":["<label>"],"custom":"<text>"}]}`; `custom` is omitted when unused and `selected` can contain zero, one, or several labels. UI interaction while the call is pending is not model context.
+
+**Token effect**: Arguments and answer JSON are data-dependent retained tokens; there is no token cost while waiting for the human.
+
+## Known Limitations and Deferred Work
+
+- **A pending question blocks the tool call until the human answers** — the tool declares no `timeout-policy` budget; cancellation rides the turn's `exec.signal` only.
+- **Answers return as JSON text** — the seam's structured `AskUserQuestionAnswer` is serialized into the tool result rather than carried as typed content blocks.

packages/ui/user-approval/README.md

@@ -8,4 +8,38 @@ Answerers are `approval/request` waterfall listeners. Return an outcome to answe
 
 `ApprovalPolicy` is `'ask'` or `'never'`. The effective value is the last `approval/policy` event, falling back to config; `setApprovalPolicy()` is the write path. `'never'` rejects before interactive dispatch and is the only policy stated in the prompt. Switches produce at most one coalesced notice whose header marker distinguishes user changes from operator/config changes.
 
-The tools pipeline consumes this seam for `ask` decisions and the sandboxed bash tool uses it for escalated retries. See the [approval-seam RFC](../../../docs/rfc/implemented/feature/2026-07-06-approval-seam.md) and [sandbox RFC](../../../docs/rfc/implemented/feature/2026-07-06-sandbox.md).
+The tools pipeline routes `ask` decisions through this seam and fails closed when it is absent; the sandboxed bash tool also uses it for escalated retries. The ACP bridge is the shipped human answerer for calls it owns. Audit events remain log-only, so the model sees only the asking consumer's result. See the [approval-seam RFC](../../../docs/rfc/implemented/feature/2026-07-06-approval-seam.md) and [sandbox RFC](../../../docs/rfc/implemented/feature/2026-07-06-sandbox.md).
+
+## Model Experience
+
+### System prompt and policy notice
+
+**What the model sees**: Under `ask`, every agent request carries the ask-policy prompt section below. Under `never`, it carries the never-policy prompt section below. A policy switch injects exactly `The approval policy changed from "<old>" to "<new>" (changed by the user).` or `The approval policy changed from "<old>" to "<new>" (changed by the operator/config).` before the next step.
+
+**Token effect**: Small fixed per-request cost, larger under `never`; a change notice is conditional and retained in history.
+
+#### Ask-policy prompt section
+
+```markdown
+<!-- dsh-user-approval-policy:ask -->
+```
+
+#### Never-policy prompt section
+
+```markdown
+Approval prompts are disabled in this session: actions that require approval are rejected automatically — do not request sandbox escalation (do not set `sandbox_permissions`).
+<!-- dsh-user-approval-policy:never -->
+```
+
+### Tool outcome
+
+**What the model sees**: `approval/asked` and `approval/decided` are log-only. The model sees only the asking consumer's eventual allowed, rejected, cancelled, or unavailable tool outcome; the human permission UI is not context.
+
+**Token effect**: Zero duplicate audit tokens. A rejection may replace a normal tool result with a small retained error, while an allowance leaves the consumer's ordinary result.
+
+## Known Limitations and Deferred Work
+
+- **Requests are valid only inside an open turn** — an idle or between-turn caller throws before auditing; a durable out-of-turn approval workflow is deferred.
+- **Only one-shot grants exist** — the outcome vocabulary has `allowed-once` but no `allow-always`, remembered rule, revocation, or grant store; session policy is only `ask` / `never`.
+- **The request carries no tool arguments** — a UI must correlate `callId` with an already rendered tool call, and a call-less request cannot be presented by the shipped ACP answerer.
+- **No built-in answerer** — headless or incompletely composed deployments resolve `unavailable` and fail closed; the service itself never prompts a human.

packages/ui/user-interaction/README.md

@@ -22,3 +22,12 @@ When an answer includes `custom`, `selected` is empty; custom text is an overrid
 ## Role
 
 This is the interface package. Model-facing consumers such as `@deepseek-ai/dsh-tool-ask-user` depend on this seam; UI front doors such as the `stdio-agent` readline module and the `acp` bridge provide the provider. The loop stays unchanged: a tool call awaits a promise, and the tool result resumes the normal agent loop.
+
+## Model Experience
+
+Indirectly, through `dsh-tool-ask-user`, which retains a successful provider answer as compact JSON or one of these failures: `Error: ask_user_question was aborted before the user answered`, `Error: ask_user_question requires at least one question`, `Error: no user-interaction provider is registered`, or `Error: <message>`. Waiting for the human adds no tokens.
+
+## Known Limitations and Deferred Work
+
+- **One provider per context** — there is no routing or fan-out to multiple UIs; a second registration throws `DUPLICATE_PROVIDER`, and with none registered `ask()` throws `NO_PROVIDER` rather than degrading.
+- **The vocabulary is the question-form shape only** — selectable options plus optional custom text; richer interaction shapes (file pickers, diff-preview confirmations) have no seam vocabulary yet.